Two machines with the same printheads, the same linear guides and the same published speed can behave completely differently after eighteen months. The difference is rarely the bill of materials. It is the sequence of operations that turned those parts into a machine: how the frame was prepared before the gantry was mounted, how the ink loop was tested, how the curing module was qualified after thermal soak, and what was measured before the unit was crated.

A buyer who understands that sequence can ask better questions during evaluation and can read an acceptance record for what it is. What follows is the process a flatbed printer build should follow, with the checks that are worth requiring in writing, and the points where a shortcut taken at the factory reappears as a production problem at your site.

Why does the build sequence matter more than the bill of materials?

Assembly sequence creates alignment, not part quality.

Good components mounted onto an unsettled frame produce a machine that drifts out of tolerance, so the order of welding, settling, machining and alignment is the real quality decision.

Component lists are easy to compare because they are visible on a specification sheet. The published specifications for this range, for example, name a hard-anodised aluminium platform with a four-zone vacuum system, AC high-precision servo motors and a fibre optic data interface on the AJ2130 series and AJ3220EX. Those are inputs. What determines whether they stay in tolerance is what happened before, during and after they were installed.

The commercial consequence is straightforward: two suppliers can quote the same part numbers and produce machines with very different service lives. That is why the audit questions in a factory evaluation should be about process rather than specification, and why an acceptance record tied to a serial number carries more weight than a component list.

How is the frame prepared before assembly?

The frame is stress-relieved before final machining.

Welding and machining leave residual stress that relaxes over the first weeks, so rails mounted onto a frame that is still moving will not stay parallel once the machine reaches your floor.

A flatbed platform is a large welded and machined assembly, and the longer it is, the more that movement matters. A tolerance that is acceptable over a 2500 × 1300 mm platform becomes a different problem over a 3200 × 2000 mm bed, which is why the largest formats in a range are usually the ones with the heaviest frames. The AJ3220EX is specified at 5272 × 2842 × 1390 mm and 1850 kg; the AJ2130 series shares a 4172 × 4250 × 1390 mm envelope at the same 1850 kg.

The check to ask for is documentation of the settling interval between fabrication and final machining, and confirmation that the rails are aligned to the machined surface rather than to the welded frame. If a builder cannot describe that sequence, the alignment procedure in the field is likely to be mechanical adjustment against an inherited error.

How are gantry and motion components aligned?

Squareness and parallelism are measured, then recorded.

Gantry squareness, rail parallelism and bed flatness should each carry a measured value and a pass criterion, because those three numbers predict whether edges stay straight across a full-width board.

Motion architecture varies across this range and each choice changes the alignment procedure. The AJ3220EX is published with magnetic levitation linear motors and THK LM guides; the AJ2130G/R and AJ3220G/R are published with a linear motor and metal grating raster for position feedback. Linear motor systems remove the belt or ball-screw wear path, but they place more demand on the encoder and on the flatness of the rail bed, because there is no mechanical compliance to absorb error.

For the buyer, the useful question is not which architecture is better in the abstract but what is measured and stored. Ask for the squareness figure, the flatness figure and the reference file used for the drop-placement check, on the understanding that a copy will travel with the machine. Those numbers are the baseline for every future service visit.

What does the ink delivery system have to survive?

Pressure swings, pigment settling and the capping cycle.

Dual negative pressure holds a stable meniscus across colour and white channels, while filtration and degassing decide whether a machine that idles between shifts starts cleanly on Monday.

The ink loop is the most common source of intermittent defects because its failures are partial. A nozzle that drops out at high coverage on a large solid fill is usually a pressure or filtration symptom rather than a head failure. Published specifications across this range use dual negative pressure for both colour and white channels, which reduces ink purge and stabilises the meniscus when one channel is heavily loaded.

Two hardware details indicate how seriously a builder treats the loop. The first is capping and wiping, which seals the heads when the machine is idle and removes the ink film before each pass; the AJ2130EX is published with a redesigned capping and wiping system. The second is waste handling, because the purge volume has to go somewhere accessible: the AJ2513G/R is published with a slide-out waste ink collector, which is a maintenance question rather than an engineering one, but it decides whether an operator cleans the machine weekly or avoids the task.

How is the curing module qualified?

Measure irradiance at the substrate, after thermal soak.

UV LED output falls as the emitter warms, so a module that passes on a cold bench can under-cure after six hours of production, which shows up as poor adhesion rather than as an obvious lamp fault.

Curing is the step where factory testing is most often done under conditions that do not match service. Judging by rated lamp output rather than measured energy at the substrate plane ignores the distance from the emitter to the print, the reflectivity of the substrate, and the temperature the module reaches under load. The AJ3220 series and AJ2130 series are published with UV LED curing, and the AJ360i cylinder printer is published as an LED UV machine, so the same qualification logic applies across the range.

Ask what irradiance was measured, where the sensor was positioned, and whether the reading was taken hot or cold. Then connect it to the test that actually matters commercially: adhesion on the substrate you will run. Adhesive failure under cure starvation is assessed the same way as coating adhesion, with the ASTM D3359 tape test (ASTM D3359), and wear under handling is assessed by abrasion testing under ASTM D4060 (ASTM D4060).

Which calibration steps must happen before crating?

Bed, gantry, drops, vacuum and colour, each with a value.

A machine should leave the factory with a measured baseline for flatness, squareness, alignment, drop placement, vacuum sealing and colour output, so a later fault can be attributed.

Calibration performed only as an internal step, without a record that travels with the machine, is wasted work from the buyer's point of view. The list below is the minimum set that allows a service visit two years later to distinguish drift from damage.

What should the factory acceptance record contain?

Serial number, head batch, mode, substrate and signature.

Without these identifiers an acceptance print is a photograph; with them it becomes the baseline you compare against when the first quality complaint arrives.

The commercial value of the record is that it converts a dispute into a comparison. If a machine is delivered and a solid fill shows banding at the trailing edge, the factory baseline tells both parties whether the condition existed at dispatch or developed afterwards. Where the throughput figure is quoted, it should name the mode and colour configuration: published figures for this range run from 13.02 m²/h on the AJ2513G/R in high-quality mode to 154.3 m²/h on the AJ3220EX in draft mode, so a number without a mode is not comparable to anything.

How is the machine protected for transport?

Crating is an engineering step for a precision frame.

The gantry needs to be locked or supported so that rail loads are not carried by the bearing surfaces, and the platform needs protection from the humidity and condensation of a sea container.

Ask what is locked, what is braced and how the electronics are protected against condensation. The AJ1206 is published with packing dimensions of 275 × 129 × 165 cm and a net weight of 400 kg against a gross weight of 520 kg, which illustrates how much of the shipping mass is packaging — protection is not an afterthought in this category. Two documents are worth requesting: the crating specification, and the procedure the installation team follows when it uncrates and re-levels the machine on site.

What belongs in the installation and handover scope?

Levelling, calibration checks, RIP setup and sign-off.

Installation is where factory calibration is re-verified on your floor, so the handover should include a repeat of the key measurements rather than a demonstration print alone.

A useful handover covers four things. Physical installation: positioning, levelling and connection of power and extraction. Verification: re-measurement of the baseline figures after the machine has settled on your floor. Software: RIP configuration and the first ICC profile for your most common substrate, since colour repeatability depends on profiles rather than on the machine alone (International Color Consortium). Training: operator routines for capping, wiping, waste handling and the daily checks that protect the consumables excluded from warranty.

Site preparation should be settled before the shipping date. The flatbed models are published at AC 220 V, 50/60 Hz with a requirement above 20 A on the AJ2130 series and AJ3220EX, and a 1850 kg machine imposes a floor-loading question that is easier to answer before delivery. Extraction and operator protection follow national rules: in the United States the OSHA printing-industry guidance covers ventilation and exposure control (OSHA), and in the United Kingdom the HSE printing pages set out equivalent duties (HSE).

What should a factory audit look for on site?

The parts store, the test bay and the paperwork.

The list below is what to check on a visit; every item is either present as a document or has to be asked for, and the gaps are as informative as the answers.

• Frame settling interval documented between fabrication and final machining.
• Machined reference surfaces used for rail alignment rather than the welded frame.
• Measured values recorded for flatness, squareness and parallelism, not just a pass stamp.
• Printhead batch recording tied to machine serial numbers.
• Curing irradiance measurement position and thermal state recorded.
• Test bay with a machine under load and a record sheet at the station.
• Parts store with labelled locations, indicating stock rather than made-to-order spares.
• Declaration of conformity matching model designations to the units on the floor (European Commission, machinery).
• Crating specification and a written uncrating and re-levelling procedure.
• Waste and consumable handling guidance for the destination market (US EPA).

What the decision comes down to

The build sequence is the part of a printer that cannot be seen in a quotation. Frame settling, rail alignment to a machined reference, ink loop testing, hot curing measurement and a recorded pre-crating baseline are what separate a machine that holds tolerance from one that needs re-calibrating every quarter.

Ask for four documents before ordering: the frame settling record, the measured alignment values, the acceptance record for your serial number, and the crating and uncrating procedure. Where those exist, the specification sheet becomes a promise the factory can be held to. Background on the manufacturing operation is published on the about page, and configuration detail sits on each model page within the wide format UV flatbed range.